SUTD-MIT GLP Summer 2013
On the night before race day, we had a last burst of fire to change the large wheels to a new wheel After failing the final inspection on Saturday and Sunday was the race day, we had a serious discussion on what we should do. The vehicle couldn't move with a rider on it because of the insufficient torque that was caused by the big wheels and an...
On Saturday, we finished our electric vehicle after yet another mad rush. Everything mechanical and electrical were in place. Yet, we failed the final inspection. The vehicle could not move when a rider was on it due to the large wheels that resulted in insufficient torque. The gear ratio was insufficient to get the vehicle rolling. It appears that the initial calculations were wrong - we needed way...
Just when we thought that the steering was performing as it should, we had a problem with it becoming difficult to turn back when it was at fully turned. ...
Initially, one of the points that we failed the rolling test was that the foot rest had no metal to support it. Despite the wood being strong enough, it may not withstand the force of a feet stomping on the brakes. We had to cut new joints and new pieces of 80/20 to extend the support to the foothold. ...
The faulty throttle When the electrical system was all wired up, I was anticipating the first moment that the motor would spring to life. It didn't. We had to troubleshoot every individual part of the circuit and test them in isolation to figure our where a mistake was made. The motor was spinning uncontrollably when we were just testing out the hall effect sensors for continuity. The worst...
The Brake Pedal Brake caliper and mount When the electrical system was being done, the brakes were being made simultaneously. It took the whole night. It was difficult to find the right tension point and took some teamwork to get it up. Also, we only realised there was a better screw at the end, which made the job much simpler. Looking back, we should have planned how the...
I must honestly say that we failed to plan for a location for the switch. Lucky for us, we were able to adapt and find a neat spot in the front to place the switches. The key switch was 3D printed for better grip as the XT60 may be slightly difficult to pull. ...
We 3D printed these stoppers to fit into the wheels to hold it together with the axle. It fit snugly after some hammering and were able to hold the wheels tightly. ...
Wiring up the electrical system Soldering the Hall Effect Sensor Thanks to the collaborative spirit amongst many teams, everyone went from clueless to being able to wire up a working electrical system. The tips given by the first few teams to finish were also much appreciated. It was pretty smooth sailing until... ...
The wheel posed us a problem - how do we mount it onto the differential axle? The hole was too big for the axle and we did not have the appropriate bearings and mounts. We also considered making a hub in the centre for holding the wheel but it wasn't feasble since there wasn't anything to latch onto the wheel. After much consideration, we ended up drilling two...
The night that the frame was laser cut, we stayed up and I managed to string up the seat! It was tied very tautly, considering that I only did it when the sun rose. Don't you just wanna sit on it? ...
The mahogany 1/2" wood has finally arrived after some delays. Began to laser cut and install the wooden frame. It wasn't all that easy to laser cut the 1/2" wood. It came 2' by 4' so i had to cut it up to fit into the laser cutter. What's more, it couldn't have been...
Our aluminium waterjet parts have arrived! The rear wheel support - the rectangular brackets were designed at the last moment to hold down the bearings. As it turns out, the waterjet parts have a certain angle of cut so the openings were quite tricky to file down to the right size for the bearings. The assembled chasis with aluminium. We were so excited that we stayed up to...
To keep things up to speed, we decided to prototype the frame as soon as the chasis came up, to see if it all fits together as calculated. ...
Our latest frame with a guard In this revision, guards were added to protect the rider from the wheels. ...
First prototype of frame and how it sizes up against the wheel The frame prototype turned out well but apparently the wheel will pose a larger threat than we thought it would. The buffer zone between the rider's shoulders and the wheel may not be enough. After making some calculations with this prototype, we made some revisions to the frame. A guard will be added to protect the...
Circles - The basis of our curves! Adding a little more detail. Strings, similar to a harp More support Further refining... This will be laser cut on wood as the first frame prototype ...
To test out the technique of bending wood, we tried cutting one to see if it works. We appreciate the e-mail advice from Carolyn (a MIT student who built Zoran when she went through 2.007) to test it out and experiment with how the wood bends. Laser Cutting The first attempt of bending - broke During my first attempt, the wood broke when I applied too much force....
Wheel Chair Wheels We couldn't use bike wheels because they require a fork and it would add complications if we were to motorize it. We chose wheel chair wheels instead as they can accommodate an axle. ...
Overview of Assembly CAD Model Concept art of wooden frame - form created using simple circles Parts/joints that will be sent to water jet ...
Motor: Turnigy Aerodrive SK3 - 6364-245kv Brushless Outrunner Motor Turns: 14T Voltage: 10S Lipoly RPM/V: 245kv Internal resistance: 0.018 Ohm Max Loading: 70A Max Power: 2700W Shaft Dia: 8.0mm Bolt holes: 32mm Bolt thread: M4 Weight: 718g Motor Plug: 4mm Bullet Connector Reason behind Choice: Calculations show that 245rpm/volts is a adequate rating that can drive the go-kart to reach 30km/h under non-ideal conditions. Controller: •Frequency of Operation:...
Constants Estimated Calculations Sitting Position Force Diagram - unlikely to flip backwards ...
a study of turning angles We wanted to have a unique steering system so we explored having levers on the sides. After several quick prototypes to test out the joints and a visual representation of how it would work, we realised that the lever method of steering may not be as feasible as a simple steering wheel. a quick prototype to test the steering mechanism The problem we...
